What is Role-Based Access Control (RBAC)?

Role-based access control (RBAC) leverages defined roles and privileges to restrict systems access to authorised users. RBAC is the foundation of least-privilege access, and it can also be used to implement other access models, such as attribute-based access control (ABAC).

How does role-based access control work?

The idea behind role-based access control is simple: Limit user access to systems and data to only the bare minimum they need to do their jobs, and no more, a concept known as the principle of least privilege (sometimes abbreviated as PoLP).

In a role-based access environment, a user's role within the organisation determines the specific network permissions they're granted. This means barring lower-level employees from accessing highly sensitive information and resources, but role-based access levels are typically more granular. When RBAC is implemented properly, users shouldn't be able to access any resources outside of their assigned job areas; for example, marketing employees should not have access to developer environments, and vice versa.

Further, role-based access is used to restrict what users can do with a system or file they've been granted access to. A user may have read-only access to certain files or systems, such as databases, but read/write access to others.

RBAC vs. ABAC

Role-based access control is often used synonymously with attribute-based access control. While ABAC and RBAC are different, RBAC is frequently used in conjunction with ABAC.

ABAC is finer-grained than RBAC and can be thought of as an extension or enhancement to role-based access. While RBAC depends on a user's role within the organisation, in an ABAC model, user access rights are dependent on a combination of attributes, not just user roles. These include but are not limited to the user's role in the organisation, where they're trying to access the resources from, the device they're using, and attributes associated with the system or application they're trying to access. This enables organisations to grant access and enforce restrictions according to the risk profile of an individual user.

As an example, you may want your IT admins to be restricted from remotely accessing back-end systems unless they're using a VPN or a remote desktop connection manager, or you may want to bar all employees from accessing company resources unless they're using a company-provided device.

RBAC vs. Access Control Lists (ACLs)

An access control list (ACL) is a list of users who have access to a particular resource, along with the privileges each user has for that resource (read-only, read-write, etc.). ACLs are the foundation of the discretionary access control (DAC) model.

The most common example of ACLs and DAC in action is the Windows file system, which allows users and administrators to define individual ACLs for each object, such as a text document or a file folder.

Access control lists, usually consisting of IP addresses, are also used by network administrators to filter traffic to VPNs, web application firewalls (WAFs) and network routers and switches. The ACL can contain an "allow list" of permissible IPs or a "block list" of disallowed IPs.

If you're thinking that sounds like a lot of work, you're right. Maintaining massive allow and block lists is time-consuming and error-prone, which is why ACLs (and the DAC model) are useful only in isolated cases involving small numbers of users.

Bottom line: While RBAC defines access privileges at the group level, an ACL defines them at the individual user or IP level. This makes RBAC much less labor-intensive and error-prone than access control lists, and thus much more feasible in a business environment with dozens, hundreds, or even thousands of users.

What are the benefits of RBAC?

There are many benefits to implementing role-based access control, including:

Enhancing security

Limiting employees' access to only the resources they need to perform their jobs prevents careless or malicious insiders from deleting, exfiltrating, or compromising the integrity of files and other digital assets, such as databases and source code.

Additionally, should an external threat actor steal a set of working login credentials, RBAC and least-privilege access will prevent them from moving laterally within the network and escalating privileges.

RBAC and least-privilege access are also key components of modern zero-trust network access models.

Supporting compliance initiatives

Role-based access enables companies to meet industry and regulatory compliance requirements, including HIPAA, the GDPR and other data protection and privacy frameworks that mandate confidentiality and privacy controls for personal identifying information (PII) and other sensitive data. This is especially important in highly regulated industries such as healthcare and finance, as well as government agencies.

Reducing costs & administrative overhead

The pre-defined user roles of an RBAC model minimise administrative overhead when onboarding and offboarding employees, when employees take on new roles or job responsibilities within the company, or when the organisation needs to grant access to a vendor or third-party contractor. Granting a new user access, or changing the access of an existing user, is simply a matter of assigning them the correct role(s). Likewise, when users leave the company, IT and security administrators can quickly revoke their systems access.

By giving administrators visibility into user access and activity, RBAC enables organisations to identify areas where they can more cost-effectively use network resources, such as bandwidth and storage.

How to implement role-based access control

1. Develop a strategy that meets your company's needs.

Before jumping in and defining roles, inventory your systems to determine which resources you need to control access to. Identify systems that process or store sensitive information, such as customer databases and developer environments, as well as systems that everyone needs access to, such as company email and help desk ticketing systems.

Also examine your company's business processes, technologies, compliance requirements, and current security posture. Identify any existing gaps, such as inconsistent policy enforcement across the organisation.

Keep in mind that you may want to use RBAC in conjunction with ABAC or another model, particularly if you're implementing zero-trust network access.

2. Define user roles.

Now it's time to analyze your workforce and group users into roles that have similar access needs. Start with broad strokes – such as looking at users by department – and then refine user roles from there.

Be sure not to define too many roles, as that would defeat the purpose of using RBAC. Consider using team-to-role mapping, where users are assigned directly into teams, which can then be assigned custom roles. This will save time, improve policy consistency, reduce errors and make it easier for administrators to role-based access policies.

Also watch out for other common pitfalls, such as insufficient granularity, role overlap, and excessive exceptions for RBAC permissions.

3. Establish an appropriate governance structure.

After you define your RBAC strategy and user roles, you need a way to enforce your new policies, as well as a change management process to alter them as your business' needs change.

Develop a written access control policy containing rules and guidance for your RBAC model, including performance indicators, risk management strategies, role re-evaluation procedures and enforcement mechanisms. A clear set of rules helps prevent "role sprawl" and internal conflicts between departments and individual users.

4. Implement your RBAC model.

A large organisation, particularly one with no role-based model, may want to roll out the new plan in stages to avoid user confusion and disruption to daily operations. Anticipate that there will be problems along the way, including issues that require you to modify your original plan. This is normal, and by rolling out your plan in stages, you can more easily tackle them.

5. Maintain your RBAC model.

Users come and go. Business needs change. technology changes. The market changes. Through it all, role-based access controls won't maintain themselves. Collect feedback from your users, continuously monitor your security posture, and conduct periodic reviews of roles, role assignments, and access logs to understand what's working and what needs to be adjusted.